# Model Context Protocol (MCP)

> The Model Context Protocol is an open standard for connecting AI applications to outside tools and data, so a single integration works across compatible assistants and agents.

- Page: https://methodcrew.com/glossary/model-context-protocol
- Last updated: 2026-10-28
- Publisher: [The Method Crew](https://methodcrew.com/)

## How it works

Anthropic released MCP in November 2024, and in December 2025 [donated it to the Agentic AI Foundation](https://www.anthropic.com/news/donating-the-model-context-protocol-and-establishing-of-the-agentic-ai-foundation), a fund under the Linux Foundation. ChatGPT, Claude, Gemini, Microsoft Copilot, Cursor and Visual Studio Code support it.

The protocol has 3 roles, as the [Model Context Protocol documentation](https://modelcontextprotocol.io/docs/getting-started/intro) sets out. The host is the AI application. It opens an MCP client connection to each MCP server. A server wraps a system, such as your CRM, a database or a file store, and exposes it as tools (actions the model can call), resources (data it can read) and prompts (reusable templates). Messages use JSON-RPC 2.0. Local servers usually talk over standard input and output; remote servers use Streamable HTTP, with OAuth recommended for sign-in.

Before MCP, each assistant needed its own connector for each system. Now a server built once can serve any compliant host.

## How businesses use it

- Giving staff assistants such as Claude or ChatGPT controlled access to internal systems, for example read-only access to the ticket queue
- Letting a [custom AI agent](https://methodcrew.com/services/custom-ai-agents) use the same connectors your staff tools use
- Publishing an MCP server for your own product, so customers' assistants can work with it
- Replacing a pile of one-off integrations with a small set of maintained servers

Many SaaS vendors now publish official MCP servers. Where they do not, we build them as part of [workflow integrations](https://methodcrew.com/services/workflow-integrations).

## Where it goes wrong

MCP standardizes the connection and leaves security to you. A server with broad write access lets any connected model act with those permissions, and text inside a tool result can carry [prompt injection](https://methodcrew.com/glossary/prompt-injection). Third-party servers from unknown publishers are code running with your credentials.

Treat every server like any other integration: least-privilege scopes, separate read and write tools, approval on anything destructive, audit logs and a named owner. Also check whether you need MCP at all. A scheduled sync in [n8n](https://methodcrew.com/glossary/n8n) that moves records between 2 systems needs no model and no protocol.

## Example (hypothetical)

Hypothetical: a 100-person SaaS company's support team works in Claude every day. An internal MCP server gives it read-only tools for the billing system and ticket history, so staff can ask about an account without copying data between tabs, and refunds stay a manual step.

## Related terms

- [Function calling (tool use)](https://methodcrew.com/glossary/function-calling): Function calling lets a language model ask your software to run a named function, such as a CRM lookup, by returning the function name and arguments as JSON.
- [AI agent](https://methodcrew.com/glossary/ai-agent): An AI agent is a language model that chooses and calls tools in a loop, reading each result, until it finishes a task or hands off to a person.
- [Prompt injection](https://methodcrew.com/glossary/prompt-injection): Prompt injection is an attack where text given to a language model, typed by a user or hidden in a document, overrides the instructions the system was built with.
- [n8n](https://methodcrew.com/glossary/n8n): n8n is a workflow automation platform, self-hosted or cloud, that connects apps and APIs in visual workflows and supports custom code and AI agent steps.
- [AI guardrails](https://methodcrew.com/glossary/ai-guardrails): AI guardrails are checks placed around a language model that block, rewrite or escalate inputs and outputs that break your rules on safety, accuracy, privacy or scope.

## Services where this matters

- [n8n, Make, Zapier and API integrations](https://methodcrew.com/services/workflow-integrations): Records moved between your CRM, inbox and finance tools without CSV exports. $1,500 to $20,000 per project.
- [Custom AI agents and copilots](https://methodcrew.com/services/custom-ai-agents): Agents that look things up in your CRM or helpdesk and take the next step, with approvals. $15,000 to $90,000 per project.

## Articles that use this term

- [n8n vs Make vs Zapier: choosing an automation platform in 2026](https://methodcrew.com/insights/n8n-vs-make-vs-zapier)

Full glossary: https://methodcrew.com/glossary